Karl Alzner goes down to block a shot in front of Tomas Vokoun. (Jana Chytilova/Getty Images)

For two periods on Wednesday night, the Washington Capitals couldn’t put the finishing touch on a number of chances they piled up. After giving up a pair of goals to the Ottawa Senators within little more than five minutes, they found themselves trailing headed into the third period.

But the Capitals stuck with their new system and scored four goals in the third to seal a 5-3 victory over the Senators at Scotiabank Place.

The victory marked the Capitals’ second win in the past seven games in what has been a trying month-long stretch for the club — 5-10-1 in its last 16 outings. They improved to 2-3 under Coach Dale Hunter.

There may have been no player more frustrated early on than Alex Ovechkin, who despite a number of scoring chances found himself either foiled by Senators netminder Craig Anderson (39 saves) or just off the mark. But otherwise Ovechkin looked like his vintage self — hitting, zipping around the offensive zone and commanding attention all over the ice — and his teammates said it seemed only a matter of time before he cashed in.

When Ovechkin finally did, 13 minutes 50 seconds into the third period, it was in grand fashion to give Washington the lead once again at 3-2. Ovechkin carried the puck from his own end, down the left wing and wrapped all the way around the net until he was only a handful of feet short of the right point. He stopped sharply, changing direction back toward the net and shaking the defensive coverage of Ottawa’s Erik Karlsson, then faked a slap shot and followed with a shot that snapped past Anderson.

“I think we have great chances in first period to score, especially our line and myself, to score like three or four goals,” said Ovechkin, who recorded his first goal in seven games. “Finally got the win, that’s most important thing. Of course, it’s pretty good when you score goal — finally. I think last couple games I have good chances to score, it just doesn’t go in.”

Ovechkin finished with one point and seven shots on goal in 18 minutes 6 seconds of playing time, making the energetic impact that the Capitals need from him on a consistent basis. He might draw the attention of league officials, however, after video replays showed him appearing to spear Ottawa’s Chris Neil in the second period.

Nicklas Backstrom got the third-period scoring started 9:45 into the period when he broke Washington’s power-play drought, scoring the team’s first goal with the man-advantage since Nov. 25 against the Rangers to even the score at 2-2.

Four minutes later, Ovechkin followed with his tally to create the initial lead then Troy Brouwer added a goal just 15 seconds later, increasing Washington’s lead to 4-2 in a span of less than six minutes. Although a late tally on the power play by Milan Michalek temporarily threatened the advantage, the visitors closed out the win with John Carlson adding an empty-net tally.

“We just kind of sat back tried not to do too much, tried not to score right away,” said Brouwer of the third period. The winger recorded a Gordie Howe hat trick of a fight, assist and a goal. “Just made sure that pucks were getting out we were trying to do the right thing and not be individuals out there. It paid off.”

From the start, Wednesday night was a more composed, united outing from the Capitals as a whole. Washington got off to a strong start, limiting Ottawa and outshooting their foes, 15-6, but that control included a squandered 1:48 of a five on three. The Capitals held their zone presence, created traffic in front and took four shots on net, but there likely could have been more from a unit that has struggled to create much on the man-advantage.

Jeff Halpern gave Washington a lead early in the second period off a rebound chance. Ottawa’s Erik Condra and Nick Foligno each scored on Tomas Vokoun (31 saves) before the period concluded, however, and would send the Capitals to the dressing room trailing 2-1.

“We had a couple chances that didn’t go our way and that’s how it is in hockey,” Backstrom said. “You’ve got to keep working ,and obviously we did a good third period.”

Capitals notes: Mike Green missed a 13th straight game with a strained right groin muscle. . . .

Roman Hamrlik sat out a fourth contest with what the team has described as a lower-body injury. . . .

Matt Hendricks missed the game with a knee injury.